The invention can for example be used in the construction of mirrors for telescopes with a high or very high resolution.
Telescopes for space applications carried by satellites require large mirrors that are ultra-stable and ultra-light. For this purpose, mirrors are commonly used whose structure is made of silicon carbide (SiC) or vitro-ceramic of the Zerodur® type
Since weight is a handicap in the field of space applications, the mirrors are locally stiffened by a rear-mounted skin in order to reduce their mass. The drawback of attaching such a rear skin, even made of the same material as the stiffeners, is the nanometer-scale instability generated by the adhesive bonding providing the junction between the rear skin and the mirror. A known solution is to bond the rear skin onto the top edge of the stiffeners, but during the drying and the polymerization, the adhesive generates, by its swaging, a significant deformation and notably stresses internal to the adhesive. When aging, the adhesive gradually relaxes a part of the stresses and deforms the mirror.
Similarly, when the honeycomb structure of the mirror undergoes thermal cycling, the adhesive bond relaxes notably at the menisci resulting in a gradual freeing of the stresses and hence a very significant deformation of the polished mirror.